JP2012146406A - Led illumination circuit and led lighting fixture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an LED lighting fixture excellent in heat radiation properties, compact and of low cost, with LEDs prevented from erroneously lighting with noise injected in an AC power source line.SOLUTION: The LED lighting fixture has and a first and a second capacitors 11, 12 of the same capacitance for staying noise injected in the AC power source line as well as an LED 2 provided on the surface of an aluminum-based substrate 1, and has a rear face of the aluminum-based substrate 1 mounted on an equipment body grounded through an insulating radiation sheet 4 excellent in electric insulation and heat conduction to radiate heat generated at the LED 2 from the equipment body. Thus, the LED lighting fixture is excellent in heat radiation properties, compact, and of low cost with the LED 2 not to be erroneously lit with the noise injected in the AC power source line as the first and the second capacitors 11, 12 are electrically conducted to the rear face of the aluminum-based substrate 1 by a conduction means 30.

Description

  The present invention relates to an LED lighting circuit and an LED lighting fixture for lighting an LED with an AC power source.

Conventionally, in an LED lighting apparatus using LEDs as a light source, the lifetime of the LED is remarkably shortened when it is in a high temperature state. Therefore, it is important to improve the heat dissipation performance of the heat generated from the LED.
In a bulb-type LED lighting fixture, an LED is provided on the surface of an aluminum base substrate, the back surface of the aluminum base substrate is brought into contact with an aluminum heat sink (the outer shell of the lighting fixture), and heat generated from the LED is transmitted to the aluminum heat sink. It is made to cool (refer patent document 1).

Utility Model Registration No. 3164467

The above-described conventional bulb-type LED lighting fixture dissipates heat generated from the LED from an aluminum heat sink, which is an outer skin of the lighting fixture. Therefore, the aluminum heat sink requires a large heat dissipation area. Large, the entire lighting fixture is large and expensive.
On the other hand, in a range hood, a lighting fixture may be attached to the hood main body, but it is difficult to attach the above-described bulb-shaped LED lighting fixture to the hood main body because of the installation space of the lighting fixture in the hood main body or the price. Sometimes.

As a result of earnest, research and experiment, the present inventors have made the following LED lighting circuit and LED lighting fixture that are excellent in the heat dissipation performance of heat generated from the LED and can be made small and low in price. I found out.
That is, the hood body of the range hood is made of metal, and since a wide area is in contact with air, pay attention to the fact that it has a wide heat dissipation area, and attach an aluminum base substrate with LEDs to the hood body, The generated heat is dissipated from the hood body.
By doing in this way, since the big heat sink like the conventional one is unnecessary, it was able to be set as the LED lighting fixture which was small, was cheap, and was excellent in heat dissipation performance.

However, in the case described above, there has been a problem that the LED is lit up or lightly lit up.
The cause of this is that the hood body is grounded, so when noise (leakage current) is injected from the AC power line, the noise flows from the aluminum base board to the hood body, and this noise (leakage current) ) Flows to the LED, it is considered that the LED is erroneously lit as described above.
In particular, when the LED is turned on by flowing AC 100V directly from the AC power supply to the LED, the aforementioned erroneous lighting of the LED remarkably appears.

  In the above-described conventional bulb-type LED lighting fixture, the aluminum heat sink is electrically insulated from the equipment body and is not grounded. Since this noise did not flow, there was no false lighting.

  It is an object of the present invention to be excellent in the heat dissipation performance of the heat generated from the LED, to be small and inexpensive, and to prevent the LED from being erroneously turned on by noise injected into the AC power line. LED lighting circuit and LED lighting fixture.

The LED illumination circuit of the present invention includes an LED illumination unit 3 provided with an LED 2 on the surface of an aluminum base substrate 1 and attached to the apparatus body so that the back surface of the aluminum base substrate 1 is electrically insulated and heat is transmitted. An LED lighting circuit that is lit by connecting the LED 2 to an AC power source,
An LED illumination having a capacitor for keeping noise injected into the AC power supply lines 5 and 6 connected to the LED 2 and electrically connecting the capacitor to the back side of the aluminum base substrate 1 Circuit.

The LED lighting circuit of the present invention connects two AC power supply lines 5 and 6 to the LED 2,
One end of the first capacitor 11 is connected to one AC power line 5, and one end of a second capacitor 12 having the same capacitance as that of the first capacitor 11 is connected to the other AC power line 6. The noise injected into the lines 5 and 6 is retained by the first and second capacitors 11 and 12,
The other end of the first capacitor 11 and the other end of the second capacitor 12 can be electrically connected to the back side of the aluminum base substrate 1, respectively.
In this way, the noise injected into the two AC power supply lines 5 and 6 can be retained by the first and second capacitors 11 and 12.

  In the LED illumination circuit of the present invention, the other end of the first capacitor 11 and the other end of the second capacitor 12 are connected by a connection line 13, and this connection line 13 is electrically connected to the back side of the aluminum base substrate 1 by a conduction line 14. Can be connected.

  In the LED lighting circuit of the present invention, a varistor 7 and a capacitor 8 can be connected between the two AC power supply lines 5 and 6.

  The LED illumination circuit of the present invention can be attached by contacting the back surface of the aluminum base substrate 1 with the device main body via the insulating heat radiating sheet 4.

The LED lighting apparatus of the present invention has an LED 2, a first capacitor 11 and a second capacitor 12 having the same capacitance on the surface of an aluminum base substrate 1, and the back surface of the aluminum base substrate 1 is electrically insulated and thermally An LED lighting apparatus that is attached to a grounded device body through a member having excellent conductivity,
The LED lighting apparatus is characterized in that a front surface side and a back surface side of the aluminum base substrate 1 are electrically connected so as not to cause a potential difference.

In the LED lighting apparatus of the present invention, one end of the LED 2 and one end of the first capacitor 11 are electrically connected, and the other end of the LED 2 and one end of the second capacitor 12 are electrically connected.
The other end of the first capacitor 11 and the other end of the second capacitor 12 can be electrically connected to the back side of the aluminum base substrate 1.

In the LED lighting apparatus of the present invention, an insulating layer 21 is provided on the surface of an aluminum base 20, and a power source pattern 22 is provided on the insulating layer 21 to form an aluminum base substrate 1. 2 The capacitors 11 and 12 are electrically connected,
An insulating heat dissipation sheet 4 is provided on the back surface of the aluminum base 20,
The power supply pattern 22 that electrically connects the other end of the first capacitor 11 and the other end of the second capacitor 12 and the aluminum base 20 can be electrically connected by the conduction means 30.

  In the LED lighting apparatus of the present invention, the LED 2 can be provided on the insulating layer 21 with the copper plate 2c interposed.

According to the present invention, since the heat generated from the LED 2 can be radiated from the device main body, the heat radiating function of the heat generated from the LED 2 is excellent.
And since the member for exclusive use which thermally radiates the heat | fever which generate | occur | produces from LED2 is unnecessary, it can be made small and low-cost.
Further, the noise injected into the AC power supply line is kept with a capacitor, and there is no potential difference between the front surface and the back surface of the aluminum base substrate 1, so that the LED 2 is not erroneously turned on by the noise injected into the AC power supply line. .

  According to the LED lighting apparatus of the present invention, by providing the LED 2 and the first and second capacitors 11 and 12 on the aluminum base substrate 1, it is small and easy to carry, and can be easily attached to an arbitrary apparatus body.

It is a circuit diagram which shows embodiment of the LED lighting circuit of this invention. It is a top view which shows embodiment of the LED lighting fixture of this invention. It is AA sectional drawing of FIG. It is sectional drawing which shows the use condition of the LED lighting fixture of this invention. It is sectional drawing which shows 2nd Embodiment of a conduction | electrical_connection means. It is sectional drawing which shows 3rd Embodiment of a conduction | electrical_connection means.

As shown in FIG. 1, an LED 2 is provided on the surface of an aluminum base substrate 1 to form an LED illumination unit 3.
The back surface of the aluminum base substrate 1 is electrically insulated and attached to a grounded device body having a large heat radiation area, for example, a hood body of a range hood so that heat is transmitted. For example, it is attached so as to be in contact with the device main body via the insulating heat radiating sheet 4.
One of the two AC power supply lines 5 and 6 is connected to one end 2 a of the LED 2 described above, and the other is connected to the other end 2 b of the LED 2.
A varistor 7 and a capacitor 8 are connected between the two AC power lines 5 and 6.
The varistor 7 and the capacitor 8 constitute a normal mode filter, and the noise injected into the two AC power supply lines 5 and 6 is attenuated by the varistor 7 and the capacitor 8.
The one AC power line 5 is provided with a fuse 9, and the other AC power line 6 is provided with a resistor 10.

Therefore, the plugs (not shown) provided on the two AC power supply lines 5 and 6 are inserted into an outlet (not shown) and connected to an AC power source, and the LED 2 is turned on by turning on a switch (not shown).
As described above, when the LED 2 is lit, the heat generated from the LED 2 is transferred to the device body through the aluminum base substrate 1 and the insulating heat radiating sheet 4 and is radiated from the device body.
Thereby, it is excellent in the thermal radiation performance of the heat which generate | occur | produces from LED2.
In addition, since a dedicated member for heat dissipation is not necessary, it is possible to reduce the size and cost.

Noise may be injected between the AC power lines 5 and 6 and the grounded PE point.
For example, when the aforementioned switch is OFF, noise may be injected into the AC power supply lines 5 and 6, and the injected noise (leakage current) causes the aluminum base substrate 1 to be electrically insulated from the device body. If this is the case, no noise will flow from the aluminum base substrate 1 to the device body, and the LED 2 will not be erroneously lit due to the noise flow. However, if the aluminum base substrate 1 and the device body are not electrically insulated. In some cases, the LED 2 is erroneously lit.

For example, when a switch is provided in one AC power line 5 and a plug is inserted into an outlet so that 100 V flows through the other AC power line 6, even if the switch is turned off, the other AC power line 6 Since it is connected to an AC power source, noise may be injected into the other AC power source line 6 as indicated by a dotted line.
When a switch is provided on the other AC power line 6 and a plug is inserted so that 100V flows through the other AC power line 5, even if the switch is turned off, the AC power line 5 is Therefore, noise may be injected into one of the AC power supply lines 5 as indicated by a one-dot chain line.

As described above, it can be estimated that the reason why the LED 2 erroneously lights when noise is injected into the AC power supply lines 5 and 6 is that noise (leakage current) flows from the front surface to the back surface of the aluminum base substrate 1. By doing so, LED2 did not light up accidentally.
That is, one end of the first capacitor 11 is connected to one AC power line 5 and one end of the second capacitor 12 is connected to the other AC power line 6, and the other ends of the first and second capacitors 11, 12 are connected. Is electrically connected to the back surface of the aluminum base substrate 1 by a conduction line 14.

It is considered that the reason why the LED 2 is not erroneously turned on as described above is as follows.
When noise is injected into one AC power supply line 5 as indicated by a solid line, the noise is retained by the first and second capacitors 11 and 12, and the potential difference between points a, b, c, and d No voltage drop due to noise occurs at both ends of the LED 2 (since no current flows due to noise), the LED 2 does not light up erroneously due to noise.
In the above description, “there is no potential difference” means that there is no potential difference (potential difference of 30 to 40 V or less) larger than the magnitude at which the LED 2 is erroneously turned on.

In order to confirm that there is no potential difference as described above, the potential difference between the grounded PE point and the points a, b, c, d was measured with 100 V applied to one AC power line 5. However, it was confirmed that the point a was 100V, the point c was 95V, the point b was 96V, the point d was 96V, and there was no potential difference.
Similarly, the potential difference between the PE point and the points a, b, c, and d was measured with 100 V applied to the other AC power line 6. The point a was 95 V, the point c was 93 V, and the point b. Was 100 V, d point was 100 V, and it was confirmed that there was no potential difference.

The position where one end of the first capacitor 11 is connected to one AC power line 5 is between the point where the capacitor 8 is connected and the point where it is connected to the LED 2, and one end of the second capacitor 12 is connected to the other AC power line 6. The same applies to the position of connection to.
Further, the other end of the first capacitor 11 and the other end of the second capacitor 12 may be electrically connected to the back surface of the aluminum base substrate 1 through the conduction line 14.
By making the first capacitor 11 and the second capacitor 12 have the same capacitance, the voltage between the point a and the point b is divided into two equal parts, the voltage between the point a and the point c, and b The voltage between the point and the point c is made the same.

Next, an embodiment of the LED lighting apparatus of the present invention will be described.
As shown in FIG. 2, an LED 2, a varistor 7, a capacitor 8, a fuse 9, a resistor 10, a first capacitor 11, and a second capacitor 12 are provided on the surface of the aluminum base substrate 1, and a first terminal 15 (voltage Side) and a second terminal 16 (0V side).

As shown in FIG. 3, the aluminum base substrate 1 is provided with an insulating layer 21 on the surface of an aluminum base (aluminum plate) 20, and a power pattern 22 is provided on the insulating layer 21.
The power supply pattern 22 is provided by electrically connecting the above-described members via a pad 23, and the power supply pattern 22 is covered with an insulating coat (solder resist) 24.

On the back surface of the aluminum base 20, a member having excellent electrical insulation and thermal conductivity, for example, an insulating heat radiating sheet 4 is provided.
One AC power line 5 is connected to the first terminal 15 (voltage side), and the other AC power line 6 is connected to the second terminal 16 (0 V side).
The first terminal 15 is electrically connected to the one end 2a of the LED 2 via the fuse 9 by the first power supply pattern 22a, and the second terminal 16 is electrically connected to the other end 2b of the LED 2 via the resistor 10 by the second power supply pattern 22b. Is conductive.
A varistor 7 and a capacitor 8 are electrically connected across the first power supply pattern 22a and the second power supply pattern 22b, and one ends of the first capacitor 11 and the second capacitor 12 are connected to the first and second capacitors. The power supply patterns 22a and 22b are electrically connected.
A heat-dissipating member, for example, a copper plate 2c is provided at a portion where the LED 2 is attached to the insulating layer 21 of the aluminum base substrate 1.
The copper plate 2c is in contact with the back surface of the LED 2 so that the LED 2 is attached to the aluminum base substrate 1 so that heat generated from the LED 2 is easily transmitted to the aluminum base 20.

The third power supply pattern 22c (the surface of the aluminum base substrate 1) connecting the other end of the first capacitor 11 and the other end of the second capacitor 12 and the aluminum base 20 which is the back surface of the aluminum base substrate 1 are connected by the conduction means 30. Electrical connection (conduction) is made so that there is no potential difference between the front surface side and the back surface side of the aluminum base substrate 1. That is, they are at the same potential.
As a result, the LED 2 does not light up erroneously when noise is injected into the AC power supply lines 5 and 6 as described above.
The conducting means 30 is formed concentrically so that the holes 31, 32, 33 communicate with the third power supply pattern 22c, the insulating layer 21, and the aluminum base 20, and a bolt 34 is provided in each of the holes 31, 32, 33. The third power supply pattern 22c, the insulating layer 21, and the aluminum base 20 are clamped and supported by bolts and nuts by inserting and nuts 35 screwed into the bolts 34.

  As described above, since the LED 2 and the first and second capacitors 11 and 12 are provided on the aluminum base substrate 1, the AC power supply lines 5 and 6 are connected to the first and second terminals 15 and 16 of the aluminum base substrate 1. The LED 2 can be turned on simply by doing so, and the LED lighting apparatus is small and easy to carry, and can be easily attached to any device body.

For example, as shown in FIG. 4, the back surface of the aluminum base substrate 1 is attached to the inner surface of an aluminum lamp case 40 via an insulating heat-dissipating sheet 4, and mounting screws 41 are inserted from the through holes 1 a of the aluminum base substrate 1. Screw onto 40 and attach.
The lamp case 40 is fixedly attached to the hood main body 42 of the range hood. 43 is a translucent cover.
That is, the lamp case 40 and the hood main body 42 are device main bodies.
As described above, when the aluminum base substrate 1 is attached to the lamp case 40 with the attachment screw 41, the attachment screw 41 prevents the aluminum base substrate 1 and the lamp case 40 from being electrically connected.
For example, a flanged cylindrical spacer 44 made of an insulating material is inserted into the through hole 1 a of the aluminum base substrate 1, and the mounting screw 41 is inserted into the spacer 44 so that the mounting screw 41 is inserted into the aluminum base substrate 1. Avoid contact.

As shown in FIG. 5, the conducting means 30 may be configured such that a screw 36 is screwed into a screw hole 37 of the aluminum base 20 through holes 31 and 32.
Further, the conduction means 30 may be a through hole 38 as shown in FIG.
Further, the conduction means 30 may be a rivet (not shown).
That is, the conduction means 30 may be configured to electrically connect the third power supply pattern 22c and the aluminum base 20.

  DESCRIPTION OF SYMBOLS 1 ... Aluminum base board, 2 ... LED, 3 ... LED illumination part, 4 ... Insulation heat radiation sheet, 5 ... One AC power supply line, 6 ... The other AC power supply line, 7 ... Varistor, 8 ... Capacitor, 9 ... Fuse, DESCRIPTION OF SYMBOLS 10 ... Resistance, 11 ... 1st capacitor, 12 ... 2nd capacitor, 13 ... Connection line, 14 ... Conduction line, 15 ... 1st terminal, 16 ... 2nd terminal, 20 ... Aluminum base, 21 ... Insulating layer, 22 ... Power pattern.

Claims (9)

An LED 2 is provided on the surface of the aluminum base substrate 1, and the back surface of the aluminum base substrate 1 is provided with an LED illumination unit 3 that is electrically insulated and attached to the apparatus body so that heat can be transmitted. An LED lighting circuit that is connected and lit,
An LED illumination having a capacitor for keeping noise injected into the AC power supply lines 5 and 6 connected to the LED 2 and electrically connecting the capacitor to the back side of the aluminum base substrate 1 circuit. Two AC power lines 5 and 6 are connected to the LED 2,
One end of the first capacitor 11 is connected to one AC power line 5, and one end of a second capacitor 12 having the same capacitance as that of the first capacitor 11 is connected to the other AC power line 6. The noise injected into the lines 5 and 6 is retained by the first and second capacitors 11 and 12,
The LED lighting circuit according to claim 1, wherein the other end of the first capacitor 11 and the other end of the second capacitor 12 are electrically connected to the back side of the aluminum base substrate 1.   The other end of the first capacitor (11) and the other end of the second capacitor (12) are connected by a connection line (13), and the connection line (13) is electrically connected to the back side of the aluminum base substrate (1) by a conduction line (14). LED lighting circuit.   4. The LED lighting circuit according to claim 3, wherein a varistor and a capacitor are connected between the two AC power supply lines.   The LED lighting circuit according to any one of claims 1 to 4, wherein a back surface of the aluminum base substrate 1 is attached in contact with an apparatus main body through an insulating heat radiation sheet 4. The surface of the aluminum base substrate 1 includes the LED 2, the first capacitor 11 and the second capacitor 12 having the same capacitance, and the back surface of the aluminum base substrate 1 is interposed through a member having excellent electrical insulation and thermal conductivity. LED lighting fixtures that are attached to a grounded device body,
An LED lighting apparatus, wherein the front surface side and the back surface side of the aluminum base substrate 1 are electrically connected so as not to cause a potential difference. One end of the LED 2 and one end of the first capacitor 11 are electrically connected, and the other end of the LED 2 and one end of the second capacitor 12 are electrically connected,
The LED lighting apparatus according to claim 6, wherein the other end of the first capacitor 11 and the other end of the second capacitor 12 are electrically connected to the back side of the aluminum base substrate 1. An insulating layer 21 is provided on the surface of the aluminum base 20, and a power supply pattern 22 is provided on the insulating layer 21 to form an aluminum base substrate 1, and the LED 2 and the first and second capacitors 11, 12 are electrically connected by the power supply pattern 22. Conducted to
An insulating heat dissipation sheet 4 is provided on the back surface of the aluminum base 20,
The LED lighting apparatus according to claim 7, wherein the power supply pattern 22 that electrically connects the other end of the first capacitor 11 and the other end of the second capacitor 12 and the aluminum base 20 are electrically connected by a conduction means 30.   The LED lighting apparatus according to claim 8, wherein the LED 2 is provided on the insulating layer 21 with a copper plate 2 c interposed therebetween.

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